In the processing of a substrate, e.g., a semiconductor substrate or a glass panel such as one used in flat panel display manufacturing, plasma is often employed. As part of the processing of a substrate (plasma etching, chemical vapor deposition, plasma enhanced chemical vapor deposition, physical vapor deposition, etc.) for example, the substrate is divided into a plurality of dies, or rectangular areas, each of which will become an integrated circuit. The substrate is then processed in a series of steps in which materials are selectively removed (etching) and added (deposition) in order to form electrical components thereon.
In an exemplary plasma process, a substrate is coated with a thin film of hardened emulsion (i.e., such as a photoresist mask) prior to etching. Areas of the hardened emulsion are then selectively removed, causing parts of the underlying substrate to become exposed. The substrate is then placed in a chamber of a plasma processing system on a substrate support structure comprising a mono-polar or bi-polar electrode, called a chuck. Appropriate process gases (e.g., C4F8, C4F6, CHF3, CH2F2, CF4, CH3F, C2F4, N2, O2, HBr, Ar, Xe, He, H2, NH3, SF6, BCl3, Cl2, etc.) are then flowed into the chamber through gas passages of a gas delivery system and ionized to form a plasma to etch exposed areas of the substrate. Halogen-containing process gases are highly corrosive and can damage inner surfaces of the gas passages.